f2fs: fix fsync_inode list addition logic and avoid invalid access to memory
[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / qnx6 / super_mmi.c
1 /*
2  * QNX6 file system, Linux implementation.
3  *
4  * Version : 1.0.0
5  *
6  * History :
7  *
8  * 01-02-2012 by Kai Bankett (chaosman@ontika.net) : first release.
9  *
10  */
11
12 #include <linux/buffer_head.h>
13 #include <linux/slab.h>
14 #include <linux/crc32.h>
15 #include "qnx6.h"
16
17 static void qnx6_mmi_copy_sb(struct qnx6_super_block *qsb,
18                 struct qnx6_mmi_super_block *sb)
19 {
20         qsb->sb_magic = sb->sb_magic;
21         qsb->sb_checksum = sb->sb_checksum;
22         qsb->sb_serial = sb->sb_serial;
23         qsb->sb_blocksize = sb->sb_blocksize;
24         qsb->sb_num_inodes = sb->sb_num_inodes;
25         qsb->sb_free_inodes = sb->sb_free_inodes;
26         qsb->sb_num_blocks = sb->sb_num_blocks;
27         qsb->sb_free_blocks = sb->sb_free_blocks;
28
29         /* the rest of the superblock is the same */
30         memcpy(&qsb->Inode, &sb->Inode, sizeof(sb->Inode));
31         memcpy(&qsb->Bitmap, &sb->Bitmap, sizeof(sb->Bitmap));
32         memcpy(&qsb->Longfile, &sb->Longfile, sizeof(sb->Longfile));
33 }
34
35 struct qnx6_super_block *qnx6_mmi_fill_super(struct super_block *s, int silent)
36 {
37         struct buffer_head *bh1, *bh2 = NULL;
38         struct qnx6_mmi_super_block *sb1, *sb2;
39         struct qnx6_super_block *qsb = NULL;
40         struct qnx6_sb_info *sbi;
41         __u64 offset;
42
43         /* Check the superblock signatures
44            start with the first superblock */
45         bh1 = sb_bread(s, 0);
46         if (!bh1) {
47                 printk(KERN_ERR "qnx6: Unable to read first mmi superblock\n");
48                 return NULL;
49         }
50         sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
51         sbi = QNX6_SB(s);
52         if (fs32_to_cpu(sbi, sb1->sb_magic) != QNX6_SUPER_MAGIC) {
53                 if (!silent) {
54                         printk(KERN_ERR "qnx6: wrong signature (magic) in"
55                                         " superblock #1.\n");
56                         goto out;
57                 }
58         }
59
60         /* checksum check - start at byte 8 and end at byte 512 */
61         if (fs32_to_cpu(sbi, sb1->sb_checksum) !=
62                                 crc32_be(0, (char *)(bh1->b_data + 8), 504)) {
63                 printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
64                 goto out;
65         }
66
67         /* calculate second superblock blocknumber */
68         offset = fs32_to_cpu(sbi, sb1->sb_num_blocks) + QNX6_SUPERBLOCK_AREA /
69                                         fs32_to_cpu(sbi, sb1->sb_blocksize);
70
71         /* set new blocksize */
72         if (!sb_set_blocksize(s, fs32_to_cpu(sbi, sb1->sb_blocksize))) {
73                 printk(KERN_ERR "qnx6: unable to set blocksize\n");
74                 goto out;
75         }
76         /* blocksize invalidates bh - pull it back in */
77         brelse(bh1);
78         bh1 = sb_bread(s, 0);
79         if (!bh1)
80                 goto out;
81         sb1 = (struct qnx6_mmi_super_block *)bh1->b_data;
82
83         /* read second superblock */
84         bh2 = sb_bread(s, offset);
85         if (!bh2) {
86                 printk(KERN_ERR "qnx6: unable to read the second superblock\n");
87                 goto out;
88         }
89         sb2 = (struct qnx6_mmi_super_block *)bh2->b_data;
90         if (fs32_to_cpu(sbi, sb2->sb_magic) != QNX6_SUPER_MAGIC) {
91                 if (!silent)
92                         printk(KERN_ERR "qnx6: wrong signature (magic) in"
93                                         " superblock #2.\n");
94                 goto out;
95         }
96
97         /* checksum check - start at byte 8 and end at byte 512 */
98         if (fs32_to_cpu(sbi, sb2->sb_checksum)
99                         != crc32_be(0, (char *)(bh2->b_data + 8), 504)) {
100                 printk(KERN_ERR "qnx6: superblock #1 checksum error\n");
101                 goto out;
102         }
103
104         qsb = kmalloc(sizeof(*qsb), GFP_KERNEL);
105         if (!qsb) {
106                 printk(KERN_ERR "qnx6: unable to allocate memory.\n");
107                 goto out;
108         }
109
110         if (fs64_to_cpu(sbi, sb1->sb_serial) >
111                                         fs64_to_cpu(sbi, sb2->sb_serial)) {
112                 /* superblock #1 active */
113                 qnx6_mmi_copy_sb(qsb, sb1);
114 #ifdef CONFIG_QNX6FS_DEBUG
115                 qnx6_superblock_debug(qsb, s);
116 #endif
117                 memcpy(bh1->b_data, qsb, sizeof(struct qnx6_super_block));
118
119                 sbi->sb_buf = bh1;
120                 sbi->sb = (struct qnx6_super_block *)bh1->b_data;
121                 brelse(bh2);
122                 printk(KERN_INFO "qnx6: superblock #1 active\n");
123         } else {
124                 /* superblock #2 active */
125                 qnx6_mmi_copy_sb(qsb, sb2);
126 #ifdef CONFIG_QNX6FS_DEBUG
127                 qnx6_superblock_debug(qsb, s);
128 #endif
129                 memcpy(bh2->b_data, qsb, sizeof(struct qnx6_super_block));
130
131                 sbi->sb_buf = bh2;
132                 sbi->sb = (struct qnx6_super_block *)bh2->b_data;
133                 brelse(bh1);
134                 printk(KERN_INFO "qnx6: superblock #2 active\n");
135         }
136         kfree(qsb);
137
138         /* offset for mmi_fs is just SUPERBLOCK_AREA bytes */
139         sbi->s_blks_off = QNX6_SUPERBLOCK_AREA / s->s_blocksize;
140
141         /* success */
142         return sbi->sb;
143
144 out:
145         if (bh1 != NULL)
146                 brelse(bh1);
147         if (bh2 != NULL)
148                 brelse(bh2);
149         return NULL;
150 }